<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <script src="./jquery-1.11.1.js"></script>
  </head>
  <body>
    <!-- 封装一个可以链式调用的函数，要求至少有三次链式调用，用于修改dom元素的style -->
    <div class="box">你真是个天才！</div>
    <script>
      var obj = {
        fn: function () {
          $(".box").css("background", "red");
          return obj;
        },
        fn2: function () {
          $(".box").addClass("add");
          return obj;
        },
        fn3: function () {
          $(".box").click(function () {
            alert("总能来点惊喜");
          });
        },
      };
      obj.fn().fn2().fn3();
    </script>
  </body>
</html>
